Rainbow Heart Surprise-Inside Cake

Rainbow Heart Surprise-Inside Cake is a white cake with a rainbow heart in the middle. This is a review of Amanda Rettke’s book called Surprise-Inside Cakes. Amanda’s food blog is called I Am Baker.

Have you heard of Surprise-Inside Cakes? The concept was developed by Amanda Rettke over at iambaker.net. She also has a wonderful book called Surprise-Inside Cakes. I have the book and I love it! (Scroll to the end of this post for a sneak peek.) Amanda posted an Easter egg surprise-inside cake last month and that gave me the idea for this Rainbow Heart Surprise-Inside Cake. Click here to see my post on the Easter egg cake. If you recall, I forgot to show you the best part of the process. The part where you place the rainbow cake “cookies” in the cake pan and cover them with batter. So here ya go…

Let me show you this one first. As you can see in the Easter egg cake post, you color your cake batter in 5 different colors. (The batter is from one box of the white cake mix of your choice.) Place the batter in ziploc bags, cut a small corner and pipe the batter onto a parchment lined large cookie sheet. Then bake for about 10 minutes. Let cool. Use a heart shaped cookie cutter to cut your cake cookies.

You make the batter from another cake mix with no color. Pour a little in the bottom of a greased 9″x5″ loaf pan. Line up your cookies like so. Here’s the photo that I forgot to take when I made the Easter egg cake. Now you can really see how this process works. Isn’t it cool! Thanks, Amanda.

Pour the rest of the batter over the top of your colorful cookies. Bake for about 45 minutes or until golden brown. Let cool.

Frost the cake with your favorite buttercream frosting. I will include the recipe I used. Add sprinkles for more color!

Slice and enjoy!

Here’s a photo summary. It’s really not hard, but it is time consuming. I call it a labor of love. This is great for a special occasion. Especially for kids or kids at heart.

Here’s a sneak peek at this awesome book, available on Amazon (affiliate):

Stay tuned. I will be trying one of the cakes from this book for my daughter’s birthday next month. It will be hard for her to choose which one because there are so many beautiful cakes. The book is available now on Amazon.com.

This is one of my favorites. A cake covered in kisses with one big kiss in the middle. So cute!

Print Recipe

Rainbow Heart Surprise-Inside Cake

Ingredients

• For the Cake
• 2 boxes of white cake mix prepared according to package instructions*
• Food coloring of your choice
• Sprinkles
• *Note - keep the cake batters in 2 separate bowls. One will be colored the other stays white.
• For the Buttercream Frosting
• 1/2 cup vegetable shortening
• 1/2 cup unsalted butter softened
• 1 teaspoon vanilla
• 4 cups powdered sugar
• 2 tablespoons milk or more for thinner consistency

Instructions

• For the cake-
• Preheat oven to 350°F. Prepare one of the cake mixes according to the package instructions. Add the food coloring of your choice and mix well. I used 5 different colors. You can decide how many colors you want, then divide your batter accordingly. Place the colored batter in gallon sized resealable plastic bags, cut a small corner and pipe the batter in rows onto a parchment lined large cookie sheet. The rows should be touching. Then bake for about 8-10 minutes. Do not overbake. Let cool completely. Use a heart shaped cookie cutter to cut your cake into cookies.
• Prepare the batter from the other cake mix with no color. Pour a little in the bottom of a greased 9"x5" loaf pan. Line up your cookies, so that they are standing upright and right next to each other. They should be touching. Keep adding cookies until the pan is full of cookies from left to right. Pour the rest of the batter over the top of your colorful cookies. Bake for about 45 minutes or until golden brown. Let cool. Frost the cake with buttercream frosting. Add sprinkles for more color and have fun cutting into this beauty!
• For the frosting-
• Place shortening in large bowl and beat with an electric mixer on medium high for two minutes. Add the butter and beat until combined. With the mixer on low speed, gradually add half the sugar. Add the milk and vanilla. Beat on low for a few seconds. Keep mixer on low and add the remaining sugar. Cover mixer with a cloth, turn the mixer up to medium high and beat for 2 minutes. Add more milk if it's too thick.